| This study evaluated and analyzed the agronomic characteristics of pear germplasm resources in nanjing area,including flowering period,new shoot length and meanwhile studied and analyzed the genetic rules of the hybrid offspring of ’Cuiguan’×’Red Pear’.The experimental results are as follows.1.From the beginning of March 2018 to the end of May 2018,the flowering period of 192 pear varieties was investigated,and it was concluded that the germination period was from February 24 to March 26.The initial flowering period was from March 21 to April 8,and the final flowering period was from April 1 to April 18,lasting 28 days.In January 2017,the effective accumulated temperature is 16℃(>5℃),the effective accumulated temperature is 130.5℃(>5℃)in February,the effective accumulated temperature is 240℃(>5 ℃)in March,the effective accumulated temperature is 397 ℃(>5℃)in April.The effective accumulated temperature is 16℃(>5℃)in January 2018,the effective accumulated temperature is 38℃(>5℃)in February,the effective accumulated temperature is 157.5℃(>5℃)in March and the effective accumulated temperature is 386.5℃(>5℃)in April.The corresponding flowering compared with them,2017 is ahead of 2018.From March to May,new growth varied greatly among different varieties.Among the 117 varieties investigated,the new growth of spring ranged from 37.33 cm to 126.67 cm,with an average length of 70.84 cm.2.Varieties of resources in the field of resources for the determination of fruit agronomic traits,including single fruit weight,vertical and horizontal diameter,core diameter,peduncle length,fruit stalk coarse,soluble solid content,fruit firmness,calculating the shape indices and edible fruit rate.The results are as follows:single fruit weight distribution ranges from 30.33 g-451.00 g,average fruit weight is 164.00 g,the standard deviation is 76.18 g;The distribution range of the shape index of the varieties in the resource garden was 0.77-1.28,with an average shape index of 0.95 and a standard deviation of 0.11.For the peduncle length and the roughness of the fruit,fruit stalk length distribution range is 20.00 mm to 72.83 mm,the standard deviation is 8.10 mm;peduncle roughness distribution ranges form 1.9 mm to 6.0 mm,the standard deviation is 0.59 mm;The content of soluble solids in fruits ranged from 6.8%to 15.2%,the average content of soluble solids was 11.2%and the standard deviation was 1.45%.The fruit’s firmness mainly ranges from 105.5 g/mm2-805.5 g/mm2,with an average value of 293.5 g/mm2 and a standard deviation of 108.33 g/mm2.3.The genetic effects of fruit characters were studied by using 55 hybrid offspring of"Cuiguan" and "Red Pear",including fruit weight,fruit shape index,fruit hardness,soluble solids content and other fruit characters.The single fruit weight of the hybrid offspring of "Cuiguan" and "Red Pear" ranged from 56.80 g to 461.50 g,with an average single fruit weight of 171.01 g.85.45%of the hybrid offspring had a single fruit weight lower than the low affinity value of 241.40 g,which showed a tendency of decrease in the hybrid offspring.The fruit shape index was distributed between 0.74 and 1.14,with an average value of 0.97.The additive effect was weak,the separation of offspring was small,and there was a trend of regression to high-value parents.The fruit firmness of hybrid offspring had a genetic effect toward the middle;The content of soluble solids in hybrid offspring tends to increase,so parents with high content of soluble solids are selected for hybridization,and the hybrid offspring with high content can be obtained. |
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